From: David Vrabel <david.vrabel@csr.com>
To: Joerg Roedel <joerg.roedel@amd.com>
Cc: Kernel development list <linux-kernel@vger.kernel.org>
Subject: dma_debug_device_change() gives bogus errors
Date: Fri, 24 Apr 2009 12:20:04 +0100 [thread overview]
Message-ID: <49F1A064.6040100@csr.com> (raw)
dma_debug_device_change() gives bogus errors if a driver unmaps dma
buffers within its driver->remove() method. This is because the
BUS_NOTIFY_UNBIND_DRIVER notification is raised before calling
driver->remove() (see __device_release_driver() in drivers/base/dd.c).
By the time my driver->remove() completes, there are no DMA mappings
(debug_dma_dump_mappings() produces no output).
Also, somewhat surprisingly, it only prints the error the first time the
driver is unbound.
David
--
David Vrabel, Senior Software Engineer, Drivers
CSR, Churchill House, Cambridge Business Park, Tel: +44 (0)1223 692562
Cowley Road, Cambridge, CB4 0WZ http://www.csr.com/
next reply other threads:[~2009-04-24 11:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-24 11:20 David Vrabel [this message]
2009-04-24 12:18 ` dma_debug_device_change() gives bogus errors Joerg Roedel
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